Criteria for Selecting a CAPP System

Selecting a CAPP system, like most software selection decisions, is not an elementary process. The initial step in the selection process should be to establish the objectives that are to be achieved by implementing a CAPP system. This will vary from one company to another. The following are representative of the objectives that may be established :

1. Capture the manufacturing engineering expertise and make it available to all process planners.
2. Reduce the amount of manual effort and time required to prepare a process plan.
3. Make it easier to introduce new manufacturing technologies.
4. Provide the capability to make mass changes to existing process plans.
5. Develop optimum and consistent process plan for part families.
6. Provide a database for manufacturing knowledge that can be readily accessed.
7. Facilitate the integration of CAD and CAM.
8. Reduce the skill required to develop a process plan.
9. Reduce the number of errors made in preparing a process plan.
10. To achieve cost reduction from implementing a process planning system.
11. Provide the ability to retrieve and store standard text and graphics.

Once the objectives have been established, criteria must be developed for choosing the process planning system. The following criteria provide a basis for structuring a selection procedure :

(a) Classification and coding capabilities.

(b) Graphics capability

• CAD
• CAD database management

(c) Work instruction creation and maintenance

• Word processing
• Text and graphics storage and editing
• Global update
• Forms generation
• Automatic revision history

 (d) Process planning capabilities

• Variant, hybrid or generative
• Part family identification
• Capture knowledge of process planners
• Selection of tools, machines and operations sequence
• Calculation of standards
• Access to other vendor's standard time modules

 (e) Machining parameters

• Selection of speeds depth of cut feeds
• Determination of stock removal
• Tolerance charting

 (f) Total system consideration

• Hardware required
• Database management capabilities
• Interface to other software system
• System cost
• Ease of use
• Future upgrades

(g) Vendor qualification

• Years in bussiness
• Numbers of employees to support software
• Experience of employees